The invention relates to a device and a method for determining distance values and distance images.
Distance values can be measured between a measuring device and an object without a physical contact between the device and the object by optical methods. In these methods, the object is illuminated by the device and the light back reflected from the object is then captured by a light detector of the device.
Distance values can for example be determined by periodically modulating the light intensity which is emitted from the device and by measuring the phase difference between the emitted light and the back reflected light arriving on the detector. However, due to the periodicity of the light intensity this method results in an ambiguous distance measurement. Unambiguous distance values can be determined by measuring the time of flight between the emission of light and the arrival of the back reflected light on the detector.
For a time of flight measurement with a precision of the distance value in the order of centimeters fast electronics acting and responding in the picosecond range are required. The distance value measured by the device can therefore depend on manufacturing tolerances of the detector. If an image sensor with multiple picture elements is used for the detector, different picture elements can measure different distance values due to the manufacturing tolerances of the picture elements.